Yes, on the old/classic lines-as has been explained here a few dozen times. ONly along east coast for now=mediterranee (via west coast/atlantic no trains anymore part of the way).

Starting from Barcelona, use the 2-hourly Catalunya Express to Cerbere (times on renfe,→ cercanias/rodalies->catalunya, then search line), trainsets with just hard plastci seats-often vandalised. Pass gates in any BCN station by showing pass.

TO FR Cerbere is 1st stop in FR (former large border checks station), where spanish broad gauge ends and normal FR gauge trains start-ev 1 of 2 hrs to Perpignan-Narbonne-then on to either Montpellier-Avignon or Toulouse-connect other line here. Connections are reasonable.

TO ES ride till just over border south=Port BOu, where you change to that spanish broad gauge.

cerbere also has (maybe only in summer) a 3/week overnight train to Paris-but this you have to REServe, inland rates, much lower as over the border.

You loose time compared to the superfast TGV/AVE, but gain around 30-35€ saved!

IF you are really into unknown things trains/rails and have time, there are also 2 inland lines, 1 with short bus ride in between, the other from BCN till just near Andorra, via Puigcerda-La Tor de Carol-same procedure there as above, then FR TER train to Toulouse (but not as often)

There is. But the border is long. Could you be more specific? From where to where exactly?

I have used the Portbou - Cerbere connection several times, and can add one (minor) caveat: French immigration officials checked the passports of all incoming passengers (from Spain) at Cerbere in 2017-2018 and 2021. Check connections carefully and allow adequate time between trains (say, 30 minutes).

The point of doing this is not always clear. Seat reservations are required to board domestic high-speed trains in France and Spain (together with other Spanish long-distance trains). It’s true that the international seat-reservation charge is (at 2021) higher than the sum of the two domestic charges (e.g. for a trip Barcelona - France), but this could change. It pays to check.

East coast variant: Spanish AVE train Barcelona - Figueres, then conventional (broad-gauge) trains to the border, and onward to Perpignan. This requires a local bus ride (or long walk) between Figueres-Vilafant (AVE) and Figueres (broad-gauge) stations. The local bus fare was 1 Euro in 2021.

West coast connection is possible and useful if traveling to or from Donostia / San Sebastian. The local “EuskoTren” system operates to Hendaye (France) and service is reasonably frequent. Eurail / Interrail passes are not valid, but the fare to /from Donostia / San Sebastian is low.

It is possible to travel by EuskoTren from Hendaye to Bilbao, with a change in Donostia / San Sebastian, but note the long travel time before embarking.

Note in addition: In 2021, RENFE (Spain) fare gates did not recognize mobile passes (This can cause major headaches at unattended stations on local lines!) Many but not all RENFE staff members were aware of this.